1. Field of the Invention
This invention relates generally to systems and methods for merging product characterization information with a characterized product. More particularly, this invention relates to systems and methods for merging integrated circuit test characterization data with characterized integrated circuit die formed on a semiconductor wafer.
2. Description of Related Art
In enterprises such as integrated circuit wafer processing companies commonly referred to as “silicon foundries”, products (integrated circuit die formed on wafers) are tested and the results merged with the products for shipment to the customer. In the example of the integrated circuit wafer, the products (integrated circuit die) may be non-functioning or function at different performance levels. The test information provides characterization data for each integrated circuit die. The test information is used to sort or bin the integrated circuit die when the wafers are scribed to dice the individual integrated circuit die from the wafer.
Refer now to FIG. 1 to review the merging of the product test characterization data for products like integrated circuit die on a wafer of the prior art. A wafer 5 is processed to form the integrated circuit die. During and after the processing, the tester 10 characterizes the wafer 5 to provide a parametric and functional description of the operation of the integrated circuit die formed on the wafer 5. The parametric data maybe voltage versus current curves for active devices to describe DC parameters or the results of ring oscillators to describe AC performance of the wafers. Further, the actual functioning of the integrated circuit die may be determined. The tester 10 creates a circuit probe result file 16 that is maintained by a data retention device 15 such as a magnetic or electro-optical disk.
The data retention device 15 is in communication 20 with a customer or product engineer 30 through the engineering data analysis system 25. The engineering data analysis system 15 provides the necessary evaluation to create a yield analysis for each lot of product (wafers) 5 produced. The data retention device 15 is further in communication 37 with the circuit probe server system 35 that provides the control and testing programs for the tester 10. The circuit probe server system 35 is in communication with a program retention device 40 that contains the control and testing programs for the tester 10. The program retention device 40 further has a converter program process 50 stored for the conversion of the circuit probe result file 16 to formats desired by the customer 30. The converter program process 50 is constructed of multiple product characterization data converters 51, 52, 53, and 54 that retrieve the circuit probe result file for a product associated with the individual product characterization data converters 51, 52, 53, and 54 to generate a merged circuit probe result file 46 that is retained by the data retention device 45. The data retention device 46 is in communication 55 with the engineering data analysis system 25 to provide the merged result circuit probe file 46 for the yield analysis. The data retention device is also in communication 46 to a wafer ink probe 60 which marks the wafer 65 with the necessary binning and yield information. This is effectively the merging of the product with the product characterization data for use by the customer to determine the appropriate binning and yield of the product (wafer) 65.
All of the product characterization data converters 51, 52, 53, and 54 are constructed based on product (wafer) 5 descriptions, since each product type is unique and may have differing merging rules. This structure is not conducive to real-time processing of the product characterization data result file 16 for merging with the product and thus must be executed on a batch basis. In products such a dynamic random access memory (DRAM), the product may have a failure on its first test and characterization by the tester 10 and then be repaired. Upon its repair, the DRAM wafer is then retested and the merging of the product characterization data must be based on the results of two test and characterization operations. Again, this does not permit real-time processing of the merging of the characterization data with the product.
U.S. Pat. No. 6,049,803 (Szalwinski) describes a method for interactive documentation of a database framework and data continued in a relational database, such as, an engineering database with data related to the manufacturing and testing of semiconductor devices. Multiple documentation levels are provided such that each documentation level includes a view of the database framework with at least one documentation level including a high level view of the database framework. The documentation levels include descriptions and definitions of the views of the database framework, and the views of the database framework include descriptions and definitions of entities, attributes and schema of the data in the database. One documentation level is displayed that includes the view of the database framework. User selectable items are displayed on the display device at each documentation level. The user selectable items represent other documentation levels or other views of the database framework. The other documentation levels are accessed by actuating one of the user selectable items. The documentation levels and the views of the database framework are based on one or more driving tables included in the database. The driving tables can be modified or updated; thereby modifying or updating the documentation levels and the views of the database framework.
U.S. Pat. No. 5,841,893 (Ishikawa, et al.) provides data analysis stations respectively for a probing tester and an automatic particle inspection machine. In the data analysis station, the coordinates on which the disposition of the die are described on a product basis are equal to those on which the locations of the defects are described. Further, the station provides a function to determine which of the die have the defects. These data analysis stations are connected through a communication line. The data is analyzed on a dice basis, resulting in being able to grasp the relationship between how the defects are caused and the product character of the dice.
U.S. Pat. No. 5,761,064 (La, et al.) teaches an automated wafer defect management system in which wafer defect data is collected from wafer inspection instruments. The wafer defect data is converted into a standard data format and made available through a central database system to workstations for review, analysis, and evaluation.
U.S. Pat. No. 6,434,725 (Sommer, et al.) describes a method and system for semiconductor testing using yield correlations between global and class parameters for semiconductor die. The system and method provide for including test data for multiple tests on each of multiple die. A global parameter is assigned to each dice as a quality measure based on the test data for that dice. Values for parameter classes are determined where each parameter class represents a parameter measured for each dice tested. A correlation between the values of the parameter classes and the global parameter values for the die are then determined. The correlation for each of the parameter classes is compared to identify at least one parameter class that detracts from dice yield.